Return to Work Act 2014

JUDGMENT OF: Deputy President Judge BP Gilchrist

Judicial determination concerning a dispute about an assessment of whole person impairment (WPI) in connection with the aftermath of bilateral carpal tunnel surgery - The assessing doctor found that the worker met the criteria of having positive clinical findings of median nerve dysfunction and electrical conduction delay - She therefore assessed his impairment for post-operative impairment following carpal tunnel surgery according to the sensory and/or motor deficits as provided for by AMA5 - The compensating authority in rejecting the consequential assessment relied upon a medical opinion that suggested some discordance between a report from the treating specialist and a hand therapist and the symptoms reported to the assessor and her clinical findings and an expression of disapproval of the testing regime that she applied - It also contended that the testing conducted was either incomplete or not adequately documented and that the assessor erred by failing to call for nerve conduction studies to establish electrical conduction delay - Held that the worker gave credible evidence and there are no grounds not to accept the truthfulness of his complaints to the assessor or the findings she made on examination - Held that there was no discordance between a report from the treating specialist and a hand therapist and the symptoms reported to the assessor and her clinical findings - Held that although testing regime that she applied is endorsed by AMA5, and there is no reason to doubt her findings based on it, she did not provide adequate reasons as to why within the ranges provided for by Table 16.10 of AMA5 she selected the percentages she arrived at and an opinion from an independent medical adviser is necessary to allay concerns about the assessment - Held that there is some doubt as to the correctness of the authority of Burda v Thomas Foods International Consolidated Pty Ltd that held that post-operative nerve conduction studies are necessary to establish electrical conduction delay and that the opinion of the Full Bench of the South Australian Employment Court should be sought to resolve this in connection with the referral to an IMA - Return to Work Act 2014, South Australian Employment Tribunal Act 2014.

Burda v Thomas Foods International Consolidated Pty Ltd [2020] SAET 160

Return to Work Corporation of South Australia v Sweeny [2025] SASCCA 50

Abraham v Return to Work SA [2016] SAET 76

Dallimore v Return to Work Corporation of South Australia [2020] SASCFC 115

HJ Heinz Company Australia Ltd v Kotzman & Ors [2009] VSC 311

Kocak v Wingfoot Australia Partners Pty Ltd and Others [2012] VSCA 259; (2012) 295 ALR 730

Salf Ali v Sydney Mitchell & Co [1980] AC 198

Dial a Tow Pty Ltd v Campbell [2024] SASCA 151

State of South Australia v Barber [2001] SAWCT 100

Pashalis v Workcover [1994] SASC 5143; (1994) 63 SASR 71

Totaan v R [2022] NSWCCA 75; (2022) 108 NSWLR 17

Pond v WorkCover/Allianz Australia (Wunda Joinery) [2001] SAWCT 69

Return to Work Corporation of South Australia v Hill [2024] SAET 113

1. This is a judicial determination that concerns a dispute about an assessment of whole person impairment (WPI) in connection with the aftermath of bilateral carpal tunnel surgery.
2. At issue is whether there are any grounds upon which not to act upon an assessment by an accredited assessor. If there are, the only option available in this case would be a referral to an assessment by an Independent Medical Adviser (IMA), appointed under s 121 of the Return to Work Act 2014 (the RTW Act).
3. The applicant, Christopher Grantham, is and was at all material times a Correctional Services Officer employed by the Department of Correctional Services at the Port Augusta Prison. His work duties required him to frequently lock and unlock cell doors and other doors within the prison. He would do this hundreds of times a day and over time he began to develop pins and needles in both of his hands. He then began to experience shooting pain in his hands and his sleep became disturbed. He consulted with his general practitioner, Dr Shroff, who referred him for nerve conduction studies. This led to a referral to the orthopaedic surgeon, Dr Saies, the diagnosis of bilateral carpal tunnel syndrome, and Dr Saies' recommendation that Mr Grantham undergo bilateral endoscopic carpal tunnel release.
4. Mr Grantham underwent the surgery to his right arm on 1 September 2020 and to his left arm on 20 October 2020. The injuries and the surgeries were accepted by the Department as compensable for the purposes of the RTW Act.
5. In a report dated 3 November 2020,[1] Dr Saies stated:

Post operatively the patient has progressed satisfactorily. With regard to his right hand he reported complete resolution of his symptoms. In particular he was not experiencing pins and needles at night or during the day. Light touch was satisfactory. He was keen to get on and have the left side operated.

...

At this very early date it would seem that he has had a complete resolution of symptoms in the right hand. I wait post-operative follow up to confirm the outcome on the left. I would anticipate that this patient has a 95% chance of good to excellent outcome from carpal tunnel surgery bilaterally with complete or almost near complete resolution of all pre-operative symptoms.

...

In my opinion the patient will suffer a minor permanent impairment arising from his carpal tunnel syndrome. This is likely to be in the form of mildly reduced light touch or pin prick sensation but in my opinion this will not have any impact on his activities of daily living or work duties.[2]

1. As part of his rehabilitation following surgery, Mr Grantham attended from time to time upon SA Hand Therapy. In a note completed by Ms Erin Cunningham[3] from SA Hand Therapy, there are records of Mr Grantham's attendance upon that clinic on 3 June 2021. The note records that Mr Grantham was feeling good with the occasional odd feeling; that he was back to normal duties, he had no concerns, and he was keen to return to the gym. It also records Ms Cunningham's opinion that there was a good post operative outcome, his strength had improved, and he had good scar maturation. She also noted very minimal median neural tension.
2. Sometime later, Mr Grantham wished to explore his entitlements to lump sum compensation under the RTW Act on account of these injuries. Section 22 of the RTW Act sets out the scheme that must be applied in assessing WPI. Amongst other things, it provides that the assessment must be made in accordance with Impairment Assessment Guidelines (the Guidelines) that are issued by the Minister.
3. The assessment must be made by an accredited medical practitioner selected in accordance with the Guidelines. The worker must be given the opportunity to choose the assessor who will assess their WPI. In conformity with this, the Department provided Mr Grantham with a list of accredited doctors and out of that list, he nominated the occupational physician, Dr Christine Brown, to act as his assessor.
4. The Guidelines provide in Chapter 1.2 that they are based mainly on the American Medical Association's Guides to the Evaluation of Permanent Impairment, 5th Edition (AMA5). The two introductory chapters in AMA5 explain the purpose of and the applications and methods for performing and reporting WPI assessments.
5. They state that the criteria contained therein "provide a standardized method for physicians to determine medical impairment".[4] They set out the examiner's roles and responsibilities. They emphasise that the assessor's role "is to provide an independent, unbiased assessment", adding that"[t]horough documentation of medical findings and their impact will ensure that the reporting is fair and consistent".[5]
6. They then go on to provide that a "clear, accurate and complete report is essential to support a rating of permanent impairment".[6]
7. The Guidelines contain instructions as to how WPI assessment reports are to be completed. These are contained in Chapter 1.43-1.45, as follows:

A whole person impairment evaluation report should be accurate, comprehensive and fair. It should clearly address the question(s) being asked of the assessor. In general, the assessor will be requested to address issues such as:

• current clinical status and diagnosis, including the basis and evidence used for determining maximum medical improvement

• reasoning as to how the assessor decided to allocate an injury to a particular class and selected a percentage within a percentage range, if applicable

• the degree of whole person impairment that results from the injury, and

• the proportion of whole person impairment due to any previous injury or cause, pre-existing condition or abnormality, if any, relevant to the injury being assessed.

1.44 The report should contain factual information based on the assessor's own history taking and clinical examination. If other reports or investigations are relied upon in arriving at an opinion, these should be appropriately referenced in the assessor's report.

1.45 The evaluation report should provide a rationale consistent with the methodology and content of the Guidelines. It should include a comparison of the evaluation's key findings with the impairment criteria in the Guidelines. In rare circumstances, where the evaluation is conducted in the absence of pertinent data or information, the assessor should indicate how the degree of impairment was determined with the limited data and justify this in detail in the report.

1. The Guidelines refer to various assessable body systems and in the case of impairments of the hand these are dealt with in Chapter 2 under the heading "Upper Extremity". It states that Chapter 16 of the AMA5 applies to WPI assessment of the upper extremities subject to modifications contained within Chapter 2 of the Guidelines. Chapter 2.11 makes specific provisions for the assessment of carpal tunnel syndrome post-operatively as follows:

The assessment of carpal tunnel syndrome post-operatively is undertaken as set out in AMA5 except that Scenario 2 (AMA 5 p495), is replaced by the following:

Where there is normal sensibility and opposition strength with residual carpal tunnel syndrome symptoms, not meeting scenario 1 (AMA 5 p495), an impairment rating not to exceed 5% of the upper extremity may be justified with rationale provided for allocation within the range.

1. To put this into context, it is necessary to set out what is written in the AMA5 about carpal tunnel syndrome. It is contained in page 495 as follows:

The carpal tunnel syndrome (CTS) is the most common of nerve compression lesions and involves the median nerve at the volar aspect of the wrist. There are many presentations of CTS. Pain and parasthesias in the median nerve distribution of the hand are the usual symptoms. Pain may radiate proximally. Nocturnal parasthesias, relieved by shaking the hand, are frequently reported and can be the only symptom in the earliest stages of nerve pathology. True sensory disturbances and muscle atrophy represent later stages, when axonotmesis with axonal degeneration is also present. The symptoms, signs, and findings may include sensory or autonomic disturbances of the radial 3 ½ digits, weakness or atrophy of the thenar muscles, a positive percussion sign at the wrist, presence of Phalen's signs, and motor and sensory electroneuromyographic abnormalities. Not all symptoms are necessarily present in any one case. In isolated involvement of the recurrent branch of the median nerve, there is weakness of thumb abduction and thenar atrophy without any sensory disturbance in the hand. Sensitivity to cold may be a major presenting symptom of CTS. Certain cases may be associated with reflex dystrophy (CRPS 1). It has also been reported that 5% of individuals with CTS may have normal electrophysiologic studies.

If after an optimal recovery time following surgical decompression, an individual continues to complain of pain, paresthesias, and/or difficulties in performing certain activities, three possible scenarios can be present:

1. Positive clinical findings of median nerve dysfunction and electrical conduction delay (s): the impairment due to CTS is rated according to the sensory and/or motor deficits as described earlier.
2. Normal sensibility and opposition strength with abnormal sensory and/or motor latencies or abnormal EMG testing of the thenar muscles: a residual CTS is still present, and an impairment rating not to exceed 5% of the upper extremity may be justified.
3. Normal sensibility (two-point discrimination and Semmes-Weinstein monofilament testing), opposition strength, and nerve conduction studies: there is no objective basis for an impairment rating.

1. Table 16.5 in AMA5 sets out the rating score for digital nerve sensory impairment. It provides that a two point discrimination in the range of less than 5 mm constitutes no sensory loss, a two point discrimination in the range of 7 mm to 15 mm is a partial sensory loss, and a two point discrimination of greater than 15 mm is a total sensory loss. Dr Brown concluded Mr Grantham had a partial loss of two point discrimination.
2. Table 16.10 in AMA5 sets out the rating score for upper extremity impairment due to sensory deficits or pain resulting from peripheral nerve disorders. It contains grades from 5 to 0, with Grade 5 being no loss of sensibility, abnormal sensation or pain, warranting a rating of sensory impairment of zero sensory loss, and Grade 0 being an absence of sensibility, abnormal sensations or severe pain that prevents all activity warranting a rating of sensory impairment of 100% sensory loss.
3. Grade 2 is described as:

Decreased superficial cutaneous pain and tactile sensibility (decreased protective sensibility), with abnormal sensations or moderate pain, that may prevent some activities.

1. The range within Grade 2 is 61%-80% sensory loss.
2. Grade 3 is described as:

Decreased superficial tactile sensibility (diminished light touch and two-point discrimination) with some abnormal sensations or moderate pain, that may prevent some activities.

1. The range within Grade 3 is 26%-60% sensory loss.
2. These Grades are further discussed in AMA5. For present purposes I set out the commentary for Grade 3 and Grade 2:

Individuals in Grade 3 have diminished light touch and two-point discrimination. There is mislocalization of sensory stimuli with some abnormal or increased irritability sensations or pain that interferes with activities. Protective sensibility is normal.

Individuals in Grade 2 have decreased protective sensibility, which is defined as a conscious appreciation of pain, temperature, or pressure before tissue damage results from the stimulus. They have diminished hand function. The mislocalization and overresponse (hyperesthesia or paraesthesia, hyperpathia, or allodynia) to sensory stimuli result in decreased manipulative skills and gripping function and complaints of hand weakness. It is possible to have gross appreciation of two-point discrimination (11-15mm) at this level.[7]

1. Dr Brown examined Mr Grantham for the purposes of the assessment on 3 February 2022, and she provided her report following that examination on 25 June 2023.[8] In her report, she expressed the opinion that Mr Grantham had a 16% WPI on account of the continuing impact of his left carpal tunnel syndrome, and a 14% WPI on account of the continuing impact of his right carpal tunnel syndrome. She had noted that Mr Grantham was obese and that this condition can be associated with carpal tunnel syndrome.
2. Section 22(8)(b) of the RTW Act stipulates that "impairments from unrelated injuries or causes are to be disregarded in making an assessment". Having regard to this, Dr Brown thought it appropriate to reduce Mr Grantham's assessment of WPI by a factor of 10% to take the potential effects of his obesity into account. She therefore reduced her WPI assessment for the left arm by 2% and for the right arm by 1%. She then combined the assessments after deduction and arrived at an overall assessment of 25% WPI.
3. Dr Brown wrote a revised report dated 21 October 2023, following the receipt of a report from the consultant rheumatologist, Dr Reiter,[9] who had reviewed Dr Brown's report
4. In the revised report, Dr Brown reduced the assessment for the right arm to 10%, before making the deduction on account of obesity, resulting in a final overall assessment of 22% WPI.
5. Mr Grantham takes no issue with Dr Brown's revised assessment.
6. It would seem that the Department was surprised by the amount of Dr Brown's assessment, and through its lawyers, it sought comment on it from the consultant physician/rheumatologist, Dr Champion. Based upon his review of Dr Brown's reports, the report of Dr Saies, and the notes of SA Hand therapy, Dr Champion thought that there was discordance between Dr Saies' opinion regarding Mr Grantham's response to the surgery and the opinion of the hand therapist, when compared to the history that Dr Brown had recorded and her clinical findings. He also believed that it was necessary for Mr Grantham to undertake post operative nerve conduction studies to properly ascertain whether he has electrical conduction delay, being a pre-requisite to apply scenario 1 as set out above.
7. In light of Dr Champion's report, the Department resolved not to act upon Dr Brown's assessment of WPI. This in turn led to the lodgement of an application for review by Mr Grantham, and the hearing before me.
8. In its Statement of Issues and Contentions, the Department submitted that Dr Brown's assessment report was not compliant with the Guidelines.
9. It specified her alleged failure to identify which scenario set out at p 495 of AMA 5 as qualified by Chapter 2.11 of the Guidelines she applied.
10. It submitted that to have applied scenario 1, there needed to be positive clinical findings of median nerve dysfunction and electrical conduction delay(s) and that absent post-operative nerve conduction studies, Dr Brown had no proper basis to be satisfied that there was electrical conduction delay(s).
11. It submitted that Dr Brown's assessment was based upon an inaccurate reporting of Mr Grantham's symptoms.
12. Finally, it submitted that Dr Brown incorrectly applied Table 16.10 of AMA5.
13. As the focus of the hearing before me was Dr Brown's assessment report, it is necessary to analyse it in some detail.

1. After detailing Mr Grantham's educational and occupational history, his social and personal history, and his past medical history, Dr Brown recorded his present medical condition. She recorded that Mr Grantham informed her that he was no longer suffering from pain in either hand but that his hands continued to be weaker than previously - they were clumsy, and were not getting stronger. She noted his specific complaints as follows:
   • When handwriting, using a pen produces a feeling of tightness and discomfort.
   • Difficulty holding the steering wheel after driving for an hour - has to alternate hands to manage. His hands do start to ache.
   • He has tried to jet ski, but his hands do not feel comfortable holding the controls.
   • His hands feel clumsy, and he tends to fumble when holding bags of lollies, and opening jars.
   • Fine manipulative and repetitive and forceful activity causes problems for him.
   • He has lost feeling in his finger tips, and his pinch grip is bad He has difficulty with toilet hygiene at times, sexual activity and massage.
   • There are problems with playing the guitar, changing a car tyre and riding a motor bike.
   • Texting and holding a mobile phone are also more difficult.
2. Dr Brown then went on to note that Mr Grantham found turning keys at work awkward, and that he needed to use two hands on some big padlocks. She noted that he has problems with housework, such as chopping and whisking when cooking, using a shovel and rake, garden and power tools, a mower and whipper snipper, and a mop and broom. She noted that he found using a computer for moderate periods caused him discomfort. She noted that he had cancelled his gym membership, recording that prior to his injury he loved working with weights at the gym, but could no longer cope with these.
3. She then recorded her findings an examination. She noted that Mr Grantham had reduced sensation in his left hand and that he reported paraesthesia at the tips of his left thumb, index, middle and ring fingers. She noted that he had decreased sensation to light touch at the thumb, index, middle and ring fingers of his right hand.
4. In respect of both hands, she recorded a partial loss of two point discrimination at the tips of the thumb, index, middle and ring fingers.
5. She conducted a test identified in AMA5 as the "Semmes-Weinstein monofilament testing".[10] Dr Brown made reference to an article of unknown origin titled "Semmes-Weinstein Pressure Aesthesiometer".[11] It states that the Semmes-Weinstein Pressure Aesthesiometer was created because of the difficulty in evaluating skin sensitivity that can otherwise produce considerable variability that is often influenced by the overall emotional state of the patient. It states that it attempts to eliminate this by the use of a standardized set of nylon filaments and a consistent testing procedure. It states that the standard kit comprises of a set of hand held filaments of varying diameters. It states that an ability to discriminate the 2.83 filament is regarded as normal, and inability to discriminate at that level, but an ability to discriminate the 3.22 or 3.61 filament is regarded as diminished light touch, an inability to recognise the 3.61 filament, but an ability to recognise the 4.31 filament is a diminished protective sensation and an inability to recognise the 4.31 filament but an ability to recognise the 6.65 filament is a loss of protective sensation.
6. Dr Brown stated that the results of her testing showed that Mr Grantham could first discriminate in his left hand at the 4.31 filament in his left hand. Based on this, she determined that Mr Grantham had a diminished protective sensation in his left hand.
7. Dr Brown stated that the results of her testing showed that Mr Grantham could first discriminate in his right hand at the 3.61 filament in his right hand. Based on this, she determined that Mr Grantham had a diminished light touch in his right hand.
8. She stated that she believed that these test results were consistent with the symptoms that Mr Grantham had disclosed to her.
9. Dr Brown then conducted a grip test which showed that Mr Grantham had a grip score of 45 kgs in his right hand and a 42 kg score in his left hand. It is common ground that these results show no abnormality.
10. Based on her findings and by reference to the results of her Semmes-Weinstein testing Dr Brown reasoned that Mr Grantham's left hand impairment was in Grade 2 of Table 16.10 and she thought that the midpoint of that range, at 70%, was the appropriate rating "because of the substantial disability described by Mr Grantham". She then applied Table 16.15 of AMA5 which lists the maximum upper extremity impairment scores available for sensory deficits, which for the median nerve below the forearm is 39% upper extremity impairment. She then applied the 70% score for sensory deficit to this and calculated Mr Grantham's upper extremity impairment score was 27%, which converted to a 16% WPI.
11. Based on her findings and by reference to the results of her Semmes-Weinstein testing Dr Brown reasoned that Mr Grantham's right hand impairment was in Grade 3 of Table 16.10 and she thought that the highest end of that range at 60%, was the appropriate rating "considering the disability described". This then converted to a 14% WPI.
12. When Dr Reiter reviewed Dr Brown's report, she formed the view that if in connection with the left hand the midpoint of the range within Grade 2 was appropriate, the same approach ought to have been adopted in connection with the right hand. Had this been done, Mr Grantham's right hand impairment would be rated at the midpoint of Grade 3, which is 43%, in lieu of 60%. This equates to a 9%WPI.
13. When this was brought to Dr Brown's attention, she agreed and reduced her WPI assessment accordingly. In her oral evidence Dr Brown was asked why she changed her report following the report from Dr Reiter. She said:

Well, when I took Mr Grantham's history, he didn't really distinguish in severity between his left hand and his right hand and, for that reason, I moved the right-hand assessment on the table. I've got some room there to make my own decision. I moved it up towards the high end. But then when Dr Reiter criticised that, I thought, "Well, fair enough. I'll put it down in the middle, the way I have with the other one," and that's what I did.

1. At trial I received all the reports just mentioned, as well as affidavit evidence from Mr Grantham, and affidavits from two of his work colleagues, Debra Mathew and Daniel Mahoney. I also heard oral evidence from Mr Grantham, Dr Brown and Dr Champion.
2. Mr Grantham said that the main symptom that he felt was resolved by the surgery was pins and needles. He said that following surgery he still felt a cramping sensation in his hands, and a lack of strength in his hands, as well as discomfort and numbness. He said that these came on after performing repetitive duties at home and at work. He said that contrary to Ms Cunningham's notes, he told her that his hands were very sore and weak after physiotherapy, and that he felt frustrated over his inability to perform even minor household tasks. He suggested that her note of him "feeling good" and having "no concerns" must have related to the resolution of his pins and needles.
3. Mr Grantham said that the history recorded by Dr Brown was accurate. He said that he struggles with handwriting and when he undertakes it, he gradually starts to feel a tightness and a cramping sensation in his hands. He said that driving has become challenging and after about twenty minutes he feels the need to shake his hands to relieve the cramping and numbness sensations that he is experiencing. He spoke of a time when he attempted to ride a mate's jet ski and of him feeling a lack of strength and control in his hands when holding the throttle. He said that after the surgery he attempted to ride a mate's motorbike and that as soon as he turned the throttle, he felt inadequate strength in his hands, so he stopped riding it. He said that on an occasion he attempted to change a tyre and he struggled to accomplish it, having lacked the strength necessary to loosen the nuts on the tyre. He said that before he developed carpal tunnel syndrome, he used to enjoy playing the guitar, but now he finds it challenging, because he is unable to press on the strings. He said that he now finds cooking difficult, as he struggles with whisking, chopping and peeling. He said that when doing this for extended periods, he experiences numbness, cramps, weakness and discomfort. He said that he has problems when texting and scrolling on his phone.
4. Mr Grantham said that the residual effects of his injury remain as they were when he saw Dr Brown.
5. When he was asked about his use of the gym, he downplayed this, saying that it was not so much a fitness thing, but was more in the nature of a social outing where he could catch up with mates. He said that although his reduced strength was a factor in him stopping going to the gym, so too was the fact that the social opportunity was no longer there, and he felt that it was not worth it anymore.
6. Mr Grantham when asked about his post operation conversation with Dr Saies, said that he remembered talking to him along the lines of Dr Saies, asking "How are you feeling?", and him replying with: "I'm feeling good. There's no pins and needles."
7. When he was asked about his conversation with Ms Cunningham, he said that she asked: "Hey, how are you going? How are you feeling?", to which he replied: "Yeah, I'm feeling good." You know, "I don't have that pins and needles." But he added that he also told her that he was experiencing weakness in his hands. He said that he told her: "Look, I don't feel that my hands are getting stronger". He said: "I'm guessing Erin [Ms Cunningham] has put that down to an odd feeling". Having accepted that it was possible that he had mentioned this at an earlier session and not at the last session, which was the subject of the note, he added: " I'm not too sure. I'm pretty sure I had mentioned to her that it was - because it definitely was just an odd feeling".
8. Ms Mathew said that it was not uncommon for her to cross paths with Mr Grantham at work. She said that she recalled him often mentioning that after carrying out inspections which involved mastering up to 30 locks in one shift, he would complain that his wrist was playing up again and he was experiencing a tingling feeling. She recalled him saying that his symptoms had not subsided since his wrist surgery, and that he described a tingling feeling and aching in his hands and wrists. She said that she had not observed him having difficulty with tasks such as answering the phone, writing with a pen, or opening and closing jars, bottles or cans. She did add that she noticed that he would flex his hands after mastering the locks of cells and barriers, and that he occasionally called to say he could not come to work because of pain.
9. Mr Mahoney said that he is an Operational Supervisor at the Prison and that part of his duties involves training officers with the use of restraints and defensive techniques in connection with inmates at the Prison. He said that he assessed Mr Grantham in respect of this and he observed that he had demonstrated an ability to do this and that he had met the minimum requirements.
10. Dr Brown accepted that she did not document in her reports all of the findings that she made on testing Mr Grantham. She also accepted that the tests she conducted to test sensory impairment may have been limited to the thumb, index, middle and ring fingers (being the digits directly served by the median nerve). She said that she did not recall testing the palm or little finger, and that if she did so, she did not document this.
11. Dr Brown said that in assessing Mr Grantham's WPI she placed him in scenario 1 as outlined in paragraph 14 herein. But she accepted that she did not expressly say so in her report, and when challenged about this she said:

Well, I don't see what other scenario it could go into. I mean, there's obviously positive clinical findings of median nerve dysfunction and electrical conduction delays. It certainly doesn't go into normal sensibility and opposition strength with abnormal...And it doesn't - it doesn't go into either of the other scenarios.

1. It was put to Dr Brown that she should have obtained post operative nerve conduction tests as a means of providing objective evidence of electrical conduction delay. Whilst she accepted that the tests have their place, it was her opinion that AMA5 did not require the test to be undertaken and that she did not consider that it was necessary in this case. My impression of her evidence was that she thought that the Semmes-Weinstein monofilament testing was sufficient and that she was entitled to use her clinical judgement in concluding that there must have been electrical conduction delays.
2. By reference to the commentary set out above, Dr Brown was asked to focus on the words "decreased manipulative skills and gripping function". It was suggested to her that in light of her finding that Mr Grantham's gripping strength was normal and that objectively, his hands were not weak, by reference to Table 16.10 in AMA5, Grade 2 was not the correct fit for his left hand and that just as she had assigned Grade 3 for the right hand, she should have assigned the same Grade for the left. Dr Brown disagreed. She said: "...there's still problems with gripping function, even though objectively the hands are not weak".
3. Dr Champion commenced his evidence by expressing his disapproval of the Semmes-Weinstein testing regime in assessing WPI. He stated that its real purpose was to assess progression and recovery in nerve damage, particularly in rehabilitation units. My impression was that he regarded this testing regime as unreliable.
4. He then expressed a concern that Dr Brown assessed severe or significant sensory impairment in median nerve, in the absence of motor impairment. He said that motor and sensory impairments go along together, such that he was surprised that there was a high sensory impairment in the absence of motor impairment.
5. I note that Mr Grantham's counsel objected to this evidence on the ground that these propositions were not put directly to Dr Brown. Given some of my conclusions about Dr Brown's report, it is not necessary for me to rule upon this objection.
6. It was Dr Champion's position that carpal tunnel surgery typically results in a complete recovery and complaints of residual symptoms after surgery are relatively uncommon. Having stated that "[t]he majority of patients who have entrapment neuropathy of the median nerve at the wrist, carpal tunnel, recover fully" he accepted that what was written in Dr Saies' report and the SA Hand Therapy note were really irrelevant to his conclusion, because he thought that in all but the rarest of cases, everyone fully recovers after carpal tunnel surgery.
7. My impression of his evidence was that he had some reservations as to whether Mr Grantham was being completely candid in reporting his symptoms to Dr Brown. That said, he agreed that Mr Grantham was in the best position to identify what his symptoms were, and whether they had changed. He also seemed to accept that if the findings made by Dr Brown were accurate, this would indicate ongoing residual problems in Mr Grantham's hands following surgery and that if he had those problems, the symptoms he complained of are those that he would expect.

1. The Department contended that Dr Brown erred in her application of AMA5 by assessing Mr Grantham's upper extremity impairments at over 5% by reference to scenario 1, as set out above, without having any post-surgery conduction studies that confirmed electrical conduction delays. In connection with this submission, the Department relied upon the judgment of Cole DP in Burda v Thomas Foods International Consolidated Pty Ltd where he said:

Whilst it is the case that scenario one on p 495 of AMA 5 does not expressly articulate the need for post-surgery nerve conduction studies, the requirement is implicit in the requirement for median nerve electrical conduction delay(s) to be identified. Nerve conduction studies or similar testing will show median nerve electrical conduction delay(s).[12]

1. The Department contended that in conformity with this, absent post-operative nerve conduction studies, scenario 1 was not available. It then added that if the post-operative nerve conduction studies came back as normal, only scenarios 2 and 3 are open.
2. Next, it contended that there is a serious doubt as whether Dr Brown correctly graded Mr Grantham's impairments in accordance with Table 16.10 of AMA5.
3. It submitted that there is a question mark over the precise manner in which she administered the requisite tests that she relied upon in finding an impairment of the median nerve.
4. It said that on the history reported by Mr Grantham to Dr Brown in relation to activities, little weight could be assigned to his apparent issues with a jet ski and motor bike or his ending his gym membership, and as for the other activities in respect of which he claimed difficulty, it said that the evidence established that he could in fact carry them out, if needed. Hence, it submitted, that any deficit fell more closely with "an interference with some activities", rather than "preventing some activities", such that Grade 3 was appropriate for both hands.
5. It then contended that Dr Brown erred in her assessment of diminished grip function. It submitted that in this case there was no objective measure of decreased gripping function. It said that this adds to the doubt as to whether the sensory impairment fits comfortably within Grade 2, in relation to the left hand.
6. It then went on to say that there was an issue with Dr Brown's report because she failed to document all the findings she made and therefore provided insufficient reason for coming up with different assessments for the right and left hands. I understood it to contend that to test for consistency, Dr Brown should have also tested Mr Grantham's palm and little finger and that if Dr Brown did not carry out that testing, she erred, and that if she did undertake that testing, her reports were inadequate because they did not record these results.
7. It submitted that because the unknown provenance of the article "Semmes-Weinstein Pressure Aesthesiometer",[13] being a document that Dr Brown clearly relied upon, this of itself case a sufficient doubt over Dr Brown's assessment to warrant a second opinion. It added that having regard to Dr Champion's evidence about the potential deficiencies in Semmes-Weinstein testing regime, that this casts a significant doubt about its use in assessing WPI, and that this was an additional reason to seek an opinion from an IMA.
8. Finally, it submitted that the Tribunal should find that the note of Ms Cunningham accurately records Mr Grantham's symptoms at that time, and that if he is to be believed, it must follow that there has been an apparent deterioration between June 2021 and March 2022 when he was assessed by Dr Brown, which undermines the factual assumptions underpinning her assessment.
9. Mr Grantham's counsel submitted that I should find that he was a transparently honest witness who was plainly being truthful. He submitted that based upon the evidence, I should find that having experienced a complete eradication of his pins and needles, which would have been the focus of his attention in the early stages, when Mr Grantham got back into doing things after his recovery from surgery, he experienced symptoms of weakness or lack of strength, and cramping sensation that worsened by repetitive activity, at home and at work.
10. It was submitted that there was no basis upon which to find that there was some change between the time he had recovered from surgery, and the time when he saw Dr Brown. He noted that Dr Champion agreed that Mr Grantham was in the best position to identify what his symptoms were, and whether they had changed. He submitted that if I accept Mr Grantham as an honest witness, that was the end of that matter. He said that Mr Grantham's evidence was corroborated by Ms Mathew, as well as by Dr Brown's examination findings. He pointed to Dr Champion's evidence, where he said that if those findings are accurate, these are the symptoms that he would expect.
11. He submitted that Dr Saies' report takes the matter nowhere, because it was expressed at a time when it was too early to have made any predictions about the likely outcome. He submitted that little can be made of Ms Cunningham's note, as it was very much the product of a general discussion that forms too thin a basis to seriously doubt Mr Grantham's evidence.
12. He submitted that I should not be troubled by Dr Champion's evidence, because his evidence was coloured by his idiosyncratic view that patients almost always completely recover from carpal tunnel surgery. He submitted that this view was at odds with Dr Saies' opinion that Mr Grantham would be left with a permanent impairment, and it was inconsistent with the Guidelines and AMA5, both of which clearly contemplate that patients following carpal tunnel release surgery, may end up with a permanent impairment.
13. As to Dr Brown's alleged error in connection with her assessment, he made the point that Dr Brown appropriately tested for diminished sensation and that it is hardly surprising that someone who cannot feel properly through the tips of his or her fingers, might experience gripping dysfunction.
14. As to the complaint that Dr Brown either did not test or did not document her testing of the palm and little finger, it was said that it was appropriate for her to have focussed on the fingertips likely to be affected by residual carpal tunnel syndrome. He added that there is nothing in the Guidelines or AMA5, that requires testing of the palm or little finger.
15. As to the submission that Mr Grantham is best seen as being within Grade 3 for both hands, because this feels more like interfering with some activities, rather than preventing some activities, it was said that this is simply incorrect. The point was made that Mr Grantham is prevented from doing multiple things, like riding a jet ski, riding a motorbike, using the weights in the gym, playing the guitar, changing a tyre, and using big keys at work.
16. Finally, it was accepted that the decision of Cole DP in Burda v Thomas Foods International (Burda) was directly on point. However, it was submitted that it is plainly wrong and I ought not follow it.
17. It was submitted that the natural and ordinary meaning of the words in scenario 1, is that it requires positive clinical findings of both median nerve dysfunction and electrical conduct delay. It was argued that if the reference to electrical conduction delay was intended to refer to a requirement for nerve conduction tests or diagnostic testing, it would have said so.
18. It was submitted that this becomes even clearer when one understands scenario 1, in context of the introductory wording, which makes it clear that it is dealing with a circumstance where there are complaints of positive symptoms of carpal tunnel syndrome, and by reference to all three scenarios: scenario 1, the person being assessed has these symptoms, and they have positive clinical findings; scenario 2, the person being assessed has complaints of symptoms, but does not have positive clinical findings; scenario 3, the person being assessed has positive symptoms of carpal tunnel syndrome, but they have neither positive clinical findings, nor do they have any abnormal diagnostic studies.
19. It was further argued that an additional rationale for why it might be that scenario 1 does not require nerve conduction studies is the observation elsewhere in AMA5 that notes : "It has also been reported that 5 per cent of individuals with carpal tunnel syndrome may have normal electrophysiologic studies".[14]
20. It was submitted that Burda is either right or wrong and that if I conclude that it is wrong, I am free to ignore it, notwithstanding the expectation that this Tribunal will not depart from its own previous decisions.

1. Dr Champion might be right in saying that the Semmes-Weinstein testing is better suited to assess progression and recovery in nerve damage, rather than in assessing WPI. But given that it is effectively endorsed by AMA5, Dr Brown cannot be criticised for using that method of testing, and there is no evidence that she did not apply the test correctly or that the results she obtained were inaccurate.
2. For the reasons submitted by Mr Grantham's counsel, I do not regard the report of Dr Saies or the report of Ms Cunningham as providing any basis to conclude that there has been any relevant change in Mr Grantham's symptoms. For the same reasons, I do not find that these reports call into question the truthfulness of what Mr Grantham told Dr Brown and this Court, nor do they call into question the opinions expressed by Dr Brown.
3. I accept Dr Champion's evidence that carpal tunnel surgery frequently results in the total abatement of symptoms. That evidence accords with evidence that I have heard in other cases. Whether the rate of success is a high as he would have it, is not for me to decide. What is clear is that carpal tunnel surgery does not always result in the total or near total abatement of symptoms. The fact that the Guidelines and AMA5 make provision for the assessment of WPI following carpal tunnel surgery attests to the fact that some patients are left with permanent impairment following this surgery, that in some cases can be quite profound. Whilst the anticipated success of carpal tunnel surgery might cast a shadow over the truthfulness of Mr Grantham's reported symptoms, ultimately it comes down as to what I make of his evidence. In my view, he was not seriously challenged in cross-examination and I found him to be an honest witness.
4. The end result is that based on the evidence that I have received, I have no reason to doubt the accuracy of the history that Mr Grantham provided to Dr Brown. Nor do I have reason to doubt that the findings that she made on examination were the product of honest responses provided by him.
5. I now turn to the Department's specific complaints about Dr Brown's report.
6. I note that neither the Guidelines nor AMA5 require an assessor in a case such as this to test for sensory loss in the palm and little fingers. That said, I accept that if the assessor suspects embellishment or abnormal illness behaviour by the worker, it would be good practice for the assessor to conduct sensory testing of the palm and little finger to verify or allay that concern. But it can be safely inferred that in this case that Dr Brown did not suspect embellishment or abnormal illness behaviour by Mr Grantham. Thus, if she did not conduct this testing or, if she did, she did not document the results, these matters do not undermine her assessment report.
7. As to the complaint that Dr Brown should have characterised any deficit caused by a sensory impairment as "an interference with some activities" as opposed to "preventing some activities", it needs to be understood that there is no bright line test that determines this. In a case that could go either way, the matter is ultimately a matter for the medical judgement of the assessor. The fact that others might have exercised their medical judgement differently, does not mean that the characterisation made by Dr Brown was flawed and should be set aside.[15]
8. In this case, in my opinion Dr Brown has adequately explained by reference to the results of her Semmes-Weinstein testing why she determined that in respect of Mr Grantham's left hand, he was in Grade 2 and why in respect of his right hand, he was in Grade 3.
9. I have, however, reached a different view in connection with how she rated the impairments within these grades.
10. It needs to be firmly understood that an assessment report of WPI conducted under s 22 of the RTW Act is not just another medico-legal report providing an opinion relevant to the determination of a worker's entitlements to compensation. In the ordinary course, it will be the definitive assessment of WPI that will be binding on all parties.[16]
11. It can be seen that the range of assessment within Grade 2 and Grade 3 in Table 16.10 in AMA5 is very wide. The range is 26% to 60% in one case, and 61% to 80% in the other. Whilst the choice as to where, within that range, the assessor places the worker's impairment is also a matter for the medical judgement of the assessor, this is not a matter in respect of which the assessor has an unfettered discretion. If it were otherwise, the intention of the Guidelines and AMA 5 to promote "standardised processes which produce similar outcomes irrespective of who conducts the assessment",[17] would not be fulfilled.
12. In conformity with the expectation that the Guidelines and AMA5 will promote precision, certainty and consistency and make as objective as possible the process of estimating impairment by reference to sufficient medical and non-medical information to justify the estimate,[18] the assessor is expected to give careful consideration as to where, within a range, the worker's impairments sit, and is obliged to explain the reasoning as to how the assessor selected a percentage within that percentage range. To adopt the words of the Victorian Court of Appeal in Kocak v Wingfoot Australia Partners Pty Ltd and Others,[19] because of the status of the s 22 assessment report, the parties are entitled to expect more than the ipse dixit of the s 22 assessor as to why a particular percentage has been arrived at.[20]
13. The Guidelines and AMA5 are replete with examples of upper, middle and lower ranges. When an assessor assigns a particular figure within the range, it is incumbent upon the assessor to explain why the upper, middle or lower range, as the case may be, has been selected, and more is required than effectively saying: "it is because I say it is".
14. In my opinion, Dr Brown's statement that 70% within the 61%-80% sensory loss range for Grade 2 in Table 16.10, was the appropriate rating for Mr Grantham left hand "because of the substantial disability described by Mr Grantham" was inadequate. It provides no explanation as to why the middle of the range was selected. The same can be said of her initial statement that 60% within the 26%-60% sensory loss range within Grade 3 in Table 16.10 was the appropriate rating for Mr Grantham's right hand "considering the disability described". It provides no explanation as to why the top of the relevant range was selected.
15. Moreover, the fact that Dr Brown so readily varied the Grade 3 assessment of Mr Grantham's right hand from the highest end of the Grade 3 range to the middle of that range, gives me little confidence that she approached the issue of where Mr Grantham's impairments sat within the ranges provided in Table 16.10, with the careful consideration that the assessment required.
16. It must be accepted that that I did not receive direct submissions regarding the adequacy of Dr Brown's reasons as to why she selected the particular Grades within Table 16.10 of AMA5 or whether she approached that rating process within the Grade with the care and consideration required. However, I do not consider that this precludes me from making findings about these matters.
17. Judges "are entitled and do think for themselves".[21] Of course, this is subject to the qualification that that a finding cannot be made if it does not meet the demands of procedural fairness. But as Doyle JA observed in Dial a Tow Pty Ltd v Campbell,[22] those demands do not require the giving of notice in "every situation in which a judge intends to reason in a way not reflected in the arguments advanced".[23] The demands of procedural fairness require "a contextual approach, and often involves matters of fact and degree ... having regard to the known material and the way in which a matter has been conducted".[24] In this case, there was evidence as to Dr Brown's reasoning that led to her Grade selections. She gave evidence as to why she changed her rating within Grade 3 in respect of Mr Grantham's right hand. Mr Grantham and his counsel were on notice that the Department was contending that Dr Brown's assessment report did not comply with the Guidelines. Given that this is a de novo hearing that requires me to undertake an independent assessment of the evidence, it was entirely predictable that I might analyse the adequacy of Dr Brown's reasoning and the care and consideration that she gave in arriving at her assessment and form views about these matters.
18. Because of my concerns about these matters, I am not satisfied that Dr Brown's assessment report, as elaborated upon by her evidence, meets the expectation of being a clear, accurate and complete report that provides adequate support for the conclusions she reached. Accordingly, I find that there are good reasons not to act upon Dr Brown's assessment.[25] In my view, an opinion from an IMA is necessary to assist the Tribunal in discharging its obligation to reach the correct decision as to Mr Grantham's WPI.
19. That then leaves for consideration the issue in connection with post-operative nerve conduction studies and Burda. In connection with this, I do not accept the submission that Burda is either right or wrong and that if I conclude that it is wrong, I am free to ignore it. The fact is, that in matters of the construction of words, reasonable minds might differ as to their meaning.[26] It has been held in several cases that a difference of opinion about how words are to be construed, will generally be insufficient to warrant a conclusion that an earlier or existing interpretation is "plainly wrong".[27]
20. In Pond v WorkCover/Allianz Australia (Wunda Joinery)[28], a Full Bench of the Workers Compensation Tribunal discussed the principle of stare decisis in connection with the decisions of that Tribunal. It noted the important policy considerations involved in following precedent and the need for restraint when contemplating not following an earlier decision. It added that caution must be exercised when reconsidering the construction of a statute and stressed the particular importance of this approach in the context of a specialist jurisdiction.
21. The Full Bench then stated:

Drawing upon these observations it follows that a single Presidential Member of the Tribunal is bound to follow and indistinguishable decision of the Full Bench of the Tribunal. A single Presidential Member of the Tribunal is generally bound to follow an earlier decision of a single Presidential Member of the Tribunal unless that single Member in the later case is convinced that the earlier decision is plainly wrong**. If, however, a single Presidential Member was of that view, it might be considered appropriate to make an application to the President pursuant to s 94A(2) of the Act for the issue regarding the correctness of that earlier decision to be determined by the Full Bench**.[29] (Emphasis mine)

1. In Return to Work Corporation of South Australia v Hill[30] it was suggested by the majority that a similar approach ought apply in connection with this Tribunal. With respect, I agree. In my view, if a single member has concerns about the correctness of an earlier decision on a matter of construction, in all but an exceptional case, the appropriate course is to seek the guidance of the Full Bench.
2. Without expressing a concluded view, I accept that the correctness of the decision in Burda is not free from doubt. It concerns an important issue in connection with the assessment of WPI following operative treatment of carpal tunnel syndrome. In the circumstances, I propose referring a question of law to a Full Bench of the South Australian Employment Court pursuant to s 22(1) of the South Australian Employment Tribunal Act 2014.
3. The purpose of the referral is to obtain the Full Bench's opinion in connection with a referral to an IMA as to the proper construction of scenario 1 set out a p 495 of AMA5 in respect of assessments of WPI in connection with carpal tunnel syndrome, and, in particular, whether a finding of "Positive clinical findings of median nerve dysfunction and electrical conduction delay (s)" must be supported by post-surgery nerve conduction studies.
4. I will hear from counsel as to the precise terms of the referral. I adjourn further consideration to a directions hearing listed before me at 2.00 pm on Thursday 26 June 2025.

[12] [2020] SAET 160 at [32].

[15] Return to Work Corporation of South Australia v Sweeny [2025] SASCCA 50 at [99].

[16] Abraham v Return to Work SA [2016] SAET 76 at [53].

[17] Dallimore v Return to Work Corporation of South Australia [2020] SASCFC 115 at [34] per Stanley J.

[18] HJ Heinz Company Australia Ltd v Kotzman & Ors [2009] VSC 311 at [27] per Kyrou J.

[19] [2012] VSCA 259; (2012) 295 ALR 730.

[21] Salf Ali v Sydney Mitchell & Co [1980] AC 198 at 212 per Lord Wilberforce.

[22] [2024] SASCA 151.

[25] Abraham v Return to Work SA [2016] SAET 76 at [61].

[26] See, for example: State of South Australia v Barber [2001] SAWCT 100 at [23] where the majority, by reference to Pashalis v Workcover [1994] SASC 5143; (1994) 63 SASR 71, observed that 'the decisions of appeal courts are littered with strong dissenting judgments, on what are ...plainly questions of law". Pashalis v Workcover was a case stated to the Full Court of the Supreme Court that resulted in five Supreme Court judges coming up with three irreconcilable opinions about the construction of review provisions in the Workers Rehabilitation and Compensation Act 1986.

[27] See, for example: Totaan v R [2022] NSWCCA 75; (2022) 108 NSWLR 17 at [72].

[28] [2001] SAWCT 69.

[30] [2024] SAET 113 at [89].